Fecal bile acids, short-chain fatty acids, and bacteria after ileal pouch-anal anastomosis do not differ in patients with pouchitis

Fecal calprotectin as an indicator in risk stratification of pouchitis following ileal pouch-anal anastomosis for ulcerative colitis

BACKGROUND

Pouchitis is the most common complication following restorative proctocolectomy and ileal pouch-anal anastomosis (IPAA) for ulcerative colitis (UC). Fecal calprotectin (FC) is a noninvasive indicator of the intestinal inflammatory status. This study was conducted to evaluate the clinical value of the FC concentration for the diagnosis and risk assessment of pouchitis.

PATIENTS AND METHODS

This retrospective study involved patients who underwent IPAA for UC at Tianjin Medical University General Hospital from January 2015 to January 2019. The patients were categorized into pouchitis and non-pouchitis groups based on their Pouchitis Disease Activity Index (PDAI) score. Laboratory indicators, including the FC concentration, were collected from both groups.

RESULTS

Sixty-six patients with UC after IPAA were included in the study and divided into the non-pouchitis group (n = 40) and pouchitis group (n = 26). The correlation coefficient between the FC concentration and the PDAI score was 0.651 (p < 0.001). Receiver operating characteristic analysis showed that the FC cut-off value for predicting pouchitis was 579.60 μg/g (area under the curve, 0.938). The patients were then divided into three subgroups according to their PDAI score (0-2, 3-6, and ≥7), and significant differences in the FC concentration were found among the three subgroups. The best FC cut-off value for predicting a high risk of pouchitis (PDAI score of 3-6) was 143.25 μg/g (area under the curve, 0.876).

CONCLUSIONS

FC is a useful biomarker in patients with pouchitis. Patients are advised to regularly undergo FC measurement to monitor for pouchitis. An FC concentration in the range of 143.25-579.60 μg/g is predictive of a high risk for pouchitis, and further examination and preventive treatment are necessary in such patients.KEY MESSAGESFecal calprotectin can be used to quantify pouch inflammation.Fecal calprotectin can be used to predict a high risk of pouchitis.

Increased Fecal Bile Acid Excretion in a Significant Subset of Patients with Other Inflammatory Diarrheal Diseases

BACKGROUND

Increased fecal bile acid excretion (IBAX) occurs in a third of patients with functional diarrhea.

AIMS

To assess the prevalence of IBAX in benign inflammatory intestinal and colonic diseases presenting with chronic diarrhea.

METHODS

All patients with known inflammatory diseases or resections who underwent 48 h fecal fat and BA testing for chronic diarrhea at a single center were included. Quiescent disease was based on clinical evaluation and serum, endoscopic and imaging studies. IBAX was defined by: > 2337 µmol total BA/48 h; or primary fecal BAs > 10%; or > 4% primary BA plus > 1000 µmol total BA /48 h. Demographics, fecal weight, fecal fat, stool frequency and consistency were collected. Nonparametric statistical analyses were used for group comparisons.

RESULTS

Sixty patients had celiac disease (51 quiescent, 9 active), 66 microscopic colitis (MC: 34 collagenous, 32 lymphocytic), 18 ulcerative colitis (UC), and 47 Crohn's disease (CD). Overall, fecal fat, 48 h stool weight, frequency and consistency were not different among subgroups except for inflammatory bowel disease (IBD) based on disease location. Almost 50% patients with celiac disease and MC had IBAX, with a greater proportion with increased primary fecal BA. Among UC patients, rates of IBAX were higher with pancolonic disease. A high proportion of patients with ileal resection or CD affecting ileum or colon had IBAX. IBAX was present even with quiescent inflammation in UC or CD.

CONCLUSIONS

A significant subset of patients with MC, quiescent celiac disease and IBD had increased fecal BA excretion, a potential additional therapeutic target for persistent diarrhea.

Ten Reasons to Think About Bile Acids in Managing Inflammatory Bowel Disease

There are ten good reasons why it is important to think about abnormalities in bile acid control in inflammatory bowel disease. Before reviewing these reasons, it is relevant to review essential elements in the enterohepatic circulation, synthesis and actions of bile acids.

Treatment and prevention of pouchitis after ileal pouch-anal anastomosis for chronic ulcerative colitis

BACKGROUND

Pouchitis occurs in approximately 50% of patients following ileal pouch-anal anastomosis (IPAA) for chronic ulcerative colitis (UC).

OBJECTIVES

The primary objective was to determine the efficacy and safety of medical therapies for prevention or treatment of acute or chronic pouchitis.

SEARCH METHODS

We searched MEDLINE, Embase and CENTRAL from inception to 25 July 2018. We also searched references, trials registers, and conference proceedings.

SELECTION CRITERIA

Randomized controlled trials of prevention or treatment of acute or chronic pouchitis in adults who underwent IPAA for UC were considered for inclusion.

DATA COLLECTION AND ANALYSIS

Two authors independently screened studies for eligibility, extracted data and assessed the risk of bias. The certainty of the evidence was evaluated using GRADE. The primary outcome was clinical improvement or remission in participants with acute or chronic pouchitis, or the proportion of participants with no episodes of pouchitis after IPAA. Adverse events (AEs) was a secondary outcome. We calculated the risk ratio (RR) and corresponding 95% confidence interval (CI) for each dichotomous outcome.

MAIN RESULTS

Fifteen studies (547 participants) were included. Four studies assessed treatment of acute pouchitis. Five studies assessed treatment of chronic pouchitis. Six studies assessed prevention of pouchitis. Three studies were low risk of bias. Three studies were high risk of bias and the other studies were unclear. Acute pouchitis: All ciprofloxacin participants (7/7) achieved remission at two weeks compared to 33% (3/9) of metronidazole participants (RR 2.68, 95% CI 1.13 to 6.35, very low certainty evidence). No ciprofloxacin participants (0/7) had an AE compared to 33% (3/9) of metronidazole participants (RR 0.18, 95% CI 0.01 to 2.98; very low certainty evidence). AEs included vomiting, dysgeusia or transient peripheral neuropathy. Forty-three per cent (6/14) of metronidazole participants achieved remission at 6 weeks compared to 50% (6/12) of budesonide enema participants (RR 0.86, 95% CI 0.37 to 1.96, very low certainty evidence). Fifty per cent (7/14) of metronidazole participants improved clinically at 6 weeks compared to 58% (7/12) of budesonide enema participants (RR 0.86, 95% CI 0.42 to 1.74, very low certainty evidence). Fifty-seven per cent (8/14) of metronidazole participants had an AE compared to 25% (3/12) of budesonide enema participants (RR 2.29, 95% CI 0.78 to 6.73, very low certainty evidence). AEs included anorexia, nausea, headache, asthenia, metallic taste, vomiting, paraesthesia, and depression. Twenty-five per cent (2/8) of rifaximin participants achieved remission at 4 weeks compared to 0% (0/10) of placebo participants (RR 6.11, 95% CI 0.33 to 111.71, very low certainty evidence). Thirty-eight per cent (3/8) of rifaximin participants improved clinically at 4 weeks compared to 30% (3/10) of placebo participants (RR 1.25, 95% CI 0.34 to 4.60, very low certainty evidence). Seventy-five per cent (6/8) of rifaximin participants had an AE compared to 50% (5/10) of placebo participants (RR 1.50, 95% CI 0.72 to 3.14, very low certainty evidence). AEs included diarrhea, flatulence, nausea, proctalgia, vomiting, thirst, candida, upper respiratory tract infection, increased hepatic enzyme, and cluster headache. Ten per cent (1/10) of Lactobacillus GG participants improved clinically at 12 weeks compared to 0% (0/10) of placebo participants (RR 3.00, 95% CI 0.14 to 65.90, very low certainty evidence). Chronic pouchitis: Eighty-five per cent (34/40) of De Simone Formulation (a probiotic formulation) participants maintained remission at 9 to 12 months compared to 3% (1/36) of placebo participants (RR 20.24, 95% CI 4.28 to 95.81, 2 studies; low certainty evidence). Two per cent (1/40) of De Simone Formulation participants had an AE compared to 0% (0/36) of placebo participants (RR 2.43, 95% CI 0.11 to 55.89; low certainty evidence). AEs included abdominal cramps, vomiting and diarrhea. Fifty per cent (3/6) of adalimumab patients achieved clinical improvement at 4 weeks compared to 43% (3/7) of placebo participants (RR, 1.17, 95% CI 0.36 to 3.76, low certainty evidence). Sixty per cent (6/10) of glutamine participants maintained remission at 3 weeks compared to 33% (3/9) of butyrate participants (RR 1.80, 95% CI 0.63 to 5.16, very low certainty evidence). Forty-five per cent (9/20) of patients treated with bismuth carbomer foam enema improved clinically at 3 weeks compared to 45% (9/20) of placebo participants (RR 1.00, 95% CI 0.50 to 1.98, very low certainty evidence). Twenty-five per cent (5/20) of participants in the bismuth carbomer foam enema group had an AE compared to 35% (7/20) of placebo participants (RR 0.71, 95% CI 0.27 to 1.88, very low certainty evidence). Adverse events included diarrhea, worsening symptoms, cramping, sinusitis, and abdominal pain.

PREVENTION

At 12 months, 90% (18/20) of De Simone Formulation participants had no episodes of acute pouchitis compared to 60% (12/20) of placebo participants (RR 1.50, 95% CI 1.02 to 2.21, low certainty evidence). Another study found 100% (16/16) of De Simone Formulation participants had no episodes of acute pouchitis at 12 months compared to 92% (11/12) of the no treatment control group (RR 1.10, 95% 0.89 to 1.36, very low certainty evidence). Eighty-six per cent (6/7) of Bifidobacterium longum participants had no episodes of acute pouchitis at 6 months compared to 60% (3/5) of placebo participants (RR 1.43, 95% CI 0.66 to 3.11, very low certainty evidence). Eleven per cent (1/9) of Clostridium butyricum MIYAIRI participants had no episodes of acute pouchitis at 24 months compared to 50% (4/8) of placebo participants (RR 0.22, 95% CI 0.03 to 1.60, very low certainty evidence). Forty-six per cent (43/94) of allopurinol participants had no episodes of pouchitis at 24 months compared to 43% (39/90) of placebo participants (RR 1.06, 95% CI 0.76 to 1.46; low certainty evidence). Eighty-one per cent (21/26) of tinidazole participants had no episodes of pouchitis over 12 months compared to 58% (7/12) of placebo participants (RR 1.38, 95% CI 0.83 to 2.31, very low certainty evidence).

AUTHORS' CONCLUSIONS

The effects of antibiotics, probiotics and other interventions for treating and preventing pouchitis are uncertain. Well designed, adequately powered studies are needed to determine the optimal therapy for the treatment and prevention of pouchitis.

Treatment and prevention of pouchitis after ileal pouch-anal anastomosis for chronic ulcerative colitis

BACKGROUND

Pouchitis occurs in approximately 50% of patients following ileal pouch-anal anastomosis (IPAA) for chronic ulcerative colitis (UC).

OBJECTIVES

The primary objective was to determine the efficacy and safety of medical therapies for prevention or treatment of acute or chronic pouchitis.

SEARCH METHODS

We searched MEDLINE, Embase and CENTRAL from inception to 25 July 2018. We also searched references, trials registers, and conference proceedings.

SELECTION CRITERIA

Randomized controlled trials of prevention or treatment of acute or chronic pouchitis in adults who underwent IPAA for UC were considered for inclusion.

DATA COLLECTION AND ANALYSIS

Two authors independently screened studies for eligibility, extracted data and assessed the risk of bias. The certainty of the evidence was evaluated using GRADE. The primary outcome was clinical improvement or remission in participants with acute or chronic pouchitis, or the proportion of participants with no episodes of pouchitis after IPAA. Adverse events (AEs) was a secondary outcome. We calculated the risk ratio (RR) and corresponding 95% confidence interval (CI) for each dichotomous outcome.

MAIN RESULTS

Fifteen studies (547 participants) were included. Four studies assessed treatment of acute pouchitis. Five studies assessed treatment of chronic pouchitis. Six studies assessed prevention of pouchitis. Three studies were low risk of bias. Three studies were high risk of bias and the other studies were unclear.Acute pouchitis: All ciprofloxacin participants (7/7) achieved remission at two weeks compared to 33% (3/9) of metronidazole participants (RR 2.68, 95% CI 1.13 to 6.35, very low certainty evidence). No ciprofloxacin participants (0/7) had an AE compared to 33% (3/9) of metronidazole participants (RR 0.18, 95% CI 0.01 to 2.98; very low certainty evidence). AEs included vomiting, dysgeusia or transient peripheral neuropathy. Forty-three per cent (6/14) of metronidazole participants achieved remission at 6 weeks compared to 50% (6/12) of budesonide enema participants (RR 0.86, 95% CI 0.37 to 1.96, very low certainty evidence). Fifty per cent (7/14) of metronidazole participants improved clinically at 6 weeks compared to 58% (7/12) of budesonide enema participants (RR 0.86, 95% CI 0.42 to 1.74, very low certainty evidence). Fifty-seven per cent (8/14) of metronidazole participants had an AE compared to 25% (3/12) of budesonide enema participants (RR 2.29, 95% CI 0.78 to 6.73, very low certainty evidence). AEs included anorexia, nausea, headache, asthenia, metallic taste, vomiting, paraesthesia, and depression. Twenty-five per cent (2/8) of rifaximin participants achieved remission at 4 weeks compared to 0% (0/10) of placebo participants (RR 6.11, 95% CI 0.33 to 111.71, very low certainty evidence). Thirty-eight per cent (3/8) of rifaximin participants improved clinically at 4 weeks compared to 30% (3/10) of placebo participants (RR 1.25, 95% CI 0.34 to 4.60, very low certainty evidence). Seventy-five per cent (6/8) of rifaximin participants had an AE compared to 50% (5/10) of placebo participants (RR 1.50, 95% CI 0.72 to 3.14, very low certainty evidence). AEs included diarrhea, flatulence, nausea, proctalgia, vomiting, thirst, candida, upper respiratory tract infection, increased hepatic enzyme, and cluster headache. Ten per cent (1/10) of Lactobacillus GG participants improved clinically at 12 weeks compared to 0% (0/10) of placebo participants (RR 3.00, 95% CI 0.14 to 65.90, very low certainty evidence).Chronic pouchitis: Eighty-five per cent (34/40) of De Simone Formulation participants maintained remission at 9 to 12 months compared to 3% (1/36) of placebo participants (RR 20.24, 95% CI 4.28 to 95.81, 2 studies; low certainty evidence). Two per cent (1/40) of De Simone Formulation participants had an AE compared to 0% (0/36) of placebo participants (RR 2.43, 95% CI 0.11 to 55.89; low certainty evidence). AEs included abdominal cramps, vomiting and diarrhea. Fifty per cent (3/6) of adalimumab patients achieved clinical improvement at 4 weeks compared to 43% (3/7) of placebo participants (RR, 1.17, 95% CI 0.36 to 3.76, low certainty evidence). Sixty per cent (6/10) of glutamine participants maintained remission at 3 weeks compared to 33% (3/9) of butyrate participants (RR 1.80, 95% CI 0.63 to 5.16, very low certainty evidence). Forty-five per cent (9/20) of patients treated with bismuth carbomer foam enema improved clinically at 3 weeks compared to 45% (9/20) of placebo participants (RR 1.00, 95% CI 0.50 to 1.98, very low certainty evidence). Twenty-five per cent (5/20) of participants in the bismuth carbomer foam enema group had an AE compared to 35% (7/20) of placebo participants (RR 0.71, 95% CI 0.27 to 1.88, very low certainty evidence). Adverse events included diarrhea, worsening symptoms, cramping, sinusitis, and abdominal pain.

PREVENTION

At 12 months, 90% (18/20) of De Simone Formulation participants had no episodes of acute pouchitis compared to 60% (12/20) of placebo participants (RR 1.50, 95% CI 1.02 to 2.21, low certainty evidence). Another study found 100% (16/16) of De Simone Formulation participants had no episodes of acute pouchitis at 12 months compared to 92% (11/12) of the no treatment control group (RR 1.10, 95% 0.89 to 1.36, very low certainty evidence). Eighty-six per cent (6/7) of Bifidobacterium longum participants had no episodes of acute pouchitis at 6 months compared to 60% (3/5) of placebo participants (RR 1.43, 95% CI 0.66 to 3.11, very low certainty evidence). Eleven per cent (1/9) of Clostridium butyricum MIYAIRI participants had no episodes of acute pouchitis at 24 months compared to 50% (4/8) of placebo participants (RR 0.22, 95% CI 0.03 to 1.60, very low certainty evidence). Forty-six per cent (43/94) of allopurinol participants had no episodes of pouchitis at 24 months compared to 43% (39/90) of placebo participants (RR 1.06, 95% CI 0.76 to 1.46; low certainty evidence). Eighty-one per cent (21/26) of tinidazole participants had no episodes of pouchitis over 12 months compared to 58% (7/12) of placebo participants (RR 1.38, 95% CI 0.83 to 2.31, very low certainty evidence).

AUTHORS' CONCLUSIONS

The effects of antibiotics, probiotics and other interventions for treating and preventing pouchitis are uncertain. Well designed, adequately powered studies are needed to determine the optimal therapy for the treatment and prevention of pouchitis.

Adalimumab in the treatment of chronic pouchitis. A randomized double-blind, placebo-controlled trial

BACKGROUND

Pouchitis is a complication of ileal pouch-anal anastomosis and occurs in up to 50% of patients 10 years after IPAA with 10% developing refractory pouchitis.

OBJECTIVE

To evaluate the effect of a TNF-α inhibitor (Adalimumab) in the treatment of refractory pouchitis.

MATERIALS AND METHODS

A multicenter, randomized double-blind, placebo-controlled trial includes patients with refractory pouchitis for more than 4 weeks despite antibiotic treatment. Patients were randomized to Adalimumab or placebo for 12 weeks. Primary outcome was reduction in clinical pouchitis disease activity index (PDAI) of ≥2 at any time. Secondary endpoints were remission of pouchitis, endoscopic and histologic effect and quality of life.

RESULTS

Thirteen patients were included; six patients received active treatment and seven patients received placebo. Nine patients (5/4, Adalimumab/placebo) completed the 12-week program. Reduction in clinical PDAI ≥ 2 was achieved in three patients in each group (50%/43%, Adalimumab/placebo, p > .5). Total PDAI improved in six patients treated with Adalimumab and two patients on placebo (100%/29%, p = .13). There were no differences in secondary endpoints between the groups.

CONCLUSIONS

In this randomized controlled trial of treatment with Adalimumab in patients with refractory pouchitis, we were not able to identify any clinical benefit in the primary or secondary endpoints.

Treatment and prevention of pouchitis after ileal pouch-anal anastomosis for chronic ulcerative colitis

BACKGROUND

Pouchitis occurs in approximately 50% of patients following ileal pouch-anal anastomosis (IPAA) for chronic ulcerative colitis.

OBJECTIVES

The primary objective was to determine the efficacy and safety of medical therapies (including antibiotics, probiotics, and other agents) for prevention or treatment of acute or chronic pouchitis.

SEARCH METHODS

We searched MEDLINE, EMBASE and the Cochrane Library from inception to October 2014.

SELECTION CRITERIA

Randomized controlled trials of prevention or treatment of acute or chronic pouchitis in adults who underwent IPAA for ulcerative colitis were considered for inclusion.

DATA COLLECTION AND ANALYSIS

Two authors independently screened studies for eligibility, extracted data and assessed study quality. Methodological quality was assessed using the Cochrane risk of bias tool. The overall quality of the evidence supporting the outcomes was evaluated using the GRADE criteria. The primary outcome was the proportion of patients with clinical improvement or remission of pouchitis in patients with acute or chronic pouchitis, or the proportion of patients with no episodes of pouchitis after IPAA. The proportion of patients who developed at least one adverse event was a secondary outcome. We calculated the risk ratio (RR) and corresponding 95% confidence interval (CI) for each dichotomous outcome.

MAIN RESULTS

Thirteen studies (517 participants) were included in the review. Four studies assessed treatment of acute pouchitis. One study (16 participants) compared ciprofloxacin and metronidazole; another (26 participants) compared metronidazole to budesonide enemas; another (18 participants) compared rifaximin to placebo; and the fourth study (20 participants) compared Lactobacillus GG to placebo. Four studies assessed treatment of chronic pouchitis. One study (19 participants) compared glutamine to butyrate suppositories; another (40 participants) compared bismuth enemas to placebo; and two studies (76 participants) compared VSL#3 to placebo. Five studies assessed prevention of pouchitis. One study (40 participants) compared VSL#3 to placebo; another (28 participants) compared VLS#3 to no treatment; one study (184 participants) compared allopurinol to placebo; another (12 participants) compared the probiotic Bifidobacterium longum to placebo; and one study (38 participants) compared tinidazole to placebo. Three studies were judged to be of high quality. Two studies were judged to be low quality and the quality of the other studies was unclear. Treatment of acute pouchitis: The results of one small study (16 participants) suggest that ciprofloxacin may be more effective than metronidazole for the treatment of acute pouchitis. One hundred per cent (7/7) of ciprofloxacin patients achieved remission at two weeks compared to 33% (3/9) of metronidazole patients. A GRADE analysis indicated that the overall quality of the evidence supporting this outcome was very low due to high risk of bias (no blinding) and very sparse data (10 events). There was no difference in the proportion of patients who had at least one adverse event (RR 0.18, 95% CI 0.01 to 2.98). Adverse events included vomiting, dysgeusia or transient peripheral neuropathy. There were no differences between metronidazole and budesonide enemas in terms of clinical remission, clinical improvement or adverse events. Adverse events included anorexia, nausea, headache, asthenia, metallic taste, vomiting, paraesthesia, and depression. There were no differences between rifaximin and placebo in terms of clinical remission, clinical improvement, or adverse events. Adverse events included diarrhea, flatulence, nausea, proctalgia, vomiting, thirst, candida, upper respiratory tract infection, increased hepatic enzyme, and cluster headache. There was no difference in clinical improvement between Lactobacillus GG and placebo. The results of these studies are uncertain due to very low quality evidence. Treatment of chronic pouchitis: A pooled analysis of two studies (76 participants) suggests that VSL#3 may be more effective than placebo for maintenance of remission. Eighty-five per cent (34/40) of VLS#3 patients maintained remission at 9 to 12 months compared to 3% (1/36) of placebo patients (RR 20.24, 95% CI 4.28 to 95.81). A GRADE analysis indicated that the quality of evidence supporting this outcome was low due to very sparse data (35 events). Adverse events included abdominal cramps, vomiting and diarrhea. There was no difference in effectiveness between glutamine and butyrate suppositories for maintenance of remission. There was no difference in clinical improvement or adverse event rates between bismuth carbomer foam enemas and placebo. Adverse events included diarrhea, worsening symptoms, cramping, sinusitis, and abdominal pain. The results of these studies are uncertain due to very low quality evidence. Prevention of pouchitis: The results of one small study (40 participants) suggest that VSL#3 may be more effective than placebo for prevention of pouchitis. Ninety per cent (18/20) of VSL#3 patients had no episodes of acute pouchitis during the 12 month study compared to 60% (12/20) of placebo patients (RR 1.50, 95% CI 1.02 to 2.21). A GRADE analysis indicated that the quality of evidence supporting this outcome was low due to very sparse data (30 events). Another small study (28 participants) found that VLS#3 was not more effective than no treatment for prevention of pouchitis. Bifidobacterium longum, allopurinol and tinidazole were not more effective than placebo for prevention of pouchitis. The results of these studies are uncertain due to very low quality evidence.

AUTHORS' CONCLUSIONS

For acute pouchitis, very low quality evidence suggests that ciprofloxacin may be more effective than metronidazole. For chronic pouchitis, low quality evidence suggests that VSL#3 may be more effective than placebo for maintenance of remission. For the prevention of pouchitis, low quality evidence suggests that VSL#3 may be more effective than placebo. Well designed, adequately powered studies are needed to determine the optimal therapy for the treatment and prevention of pouchitis.

The effects of probiotics on barrier function and mucosal pouch microbiota during maintenance treatment for severe pouchitis in patients with ulcerative colitis

BACKGROUND

A total of 10-15% of patients with an ileoanal pouch develop severe pouchitis necessitating long-term use of antibiotics or pouch excision. Probiotics reduce the risk of recurrence of pouchitis, but mechanisms behind these effects are not fully understood.

AIM

To examine mucosal barrier function in pouchitis, before and after probiotic supplementation and to assess composition of mucosal pouch microbiota.

METHODS

Sixteen patients with severe pouchitis underwent endoscopy with biopsies of the pouch on three occasions: during active pouchitis; clinical remission by 4 weeks of antibiotics; after 8 weeks of subsequent probiotic supplementation (Ecologic 825, Winclove, Amsterdam, the Netherlands). Thirteen individuals with a healthy ileoanal pouch were sampled once as controls. Ussing chambers were used to assess transmucosal passage of Escherichia coli K12, permeability to horseradish peroxidase (HRP) and ⁵¹Cr-EDTA. Composition and diversity of the microbiota was analysed using Human Intestinal Tract Chip.

RESULTS

Pouchitis Disease Activity Index (PDAI) was significantly improved after antibiotic and probiotic supplementation. Escherichia coli K12 passage during active pouchitis [3.7 (3.4-8.5); median (IQR)] was significantly higher than in controls [1.7 (1.0-2.4); P < 0.01], did not change after antibiotic treatment [5.0 (3.3-7.1); P = ns], but was significantly reduced after subsequent probiotic supplementation [2.2 (1.7-3.3); P < 0.05]. No significant effects of antibiotics or probiotics were observed on composition of mucosal pouch microbiota; however, E. coli passage correlated with bacterial diversity (r = -0.40; P = 0.018). Microbial groups belonging to Bacteroidetes and Clostridium clusters IX, XI and XIVa were associated with healthy pouches.

CONCLUSIONS

Probiotics restored the mucosal barrier to E. coli and HRP in patients with pouchitis, a feasible factor in prevention of recurrence during maintenance treatment. Restored barrier function did not translate into significant changes in mucosal microbiota composition, but bacterial diversity correlated with barrier function.

Chronic use of PPI and H2 antagonists decreases the risk of pouchitis after IPAA for ulcerative colitis

INTRODUCTION

Bacteria have been implicated in the development of pouchitis after ileal pouch anal anastomosis. The change in gastric pH with the use of proton pump inhibitors and H(2) antagonists may lead to alteration of enteric bacteria. We hypothesized that chronic use of these medications would decrease the incidence of pouchitis.

METHODS

Patients who had undergone ileal pouch anal anastomosis for ulcerative colitis were classified by history of pouchitis. Patients were further classified by their use of proton pump inhibitors, H(2) blockers, antacids, and other known risk factors for pouchitis.

RESULTS

Eighty-five patients were identified. There was a statistically significant increase in the use of daily acid suppression in patients without pouchitis. There was also a statistically significant increase in the use of antacids in patients without pouchitis. Occasional use of acid suppression did not alter the rate of pouchitis.

CONCLUSIONS

Our data suggest that the daily use of proton pump inhibitors, H(2) antagonists, or antacids is associated with a decreased risk of pouchitis in ulcerative colitis. Occasional use of these agents did not seem to afford the same protection. These data suggest that altering the pH of the gastrointestinal tract may influence the development of pouchitis.

Etiology of pouchitis

Restorative proctocolectomy with ileal-pouch anal anastomosis (RPC) is the operation of choice for ulcerative colitis (UC) patients requiring surgery. It is also used for patients with familial adenomatous polyposis (FAP). Pouchitis accounts for 10% of pouch failures. It is an idiopathic inflammatory condition that may occur in up to 50% of patients after RPC for UC. It is rarely seen in FAP patients after RPC. The etiology of pouchitis remains unclear. An overlap with UC is suggested by the frequency with which pouchitis affects patients with UC compared with FAP patients. There is significant clinical evidence implicating bacteria in the pathogenesis of pouchitis. Studies using culture and molecular methods demonstrate a dysbiosis of the pouch microbiota in pouchitis. Risk factors, genetic associations, and serological markers of pouchitis suggest that the interactions between the host immune responses and the pouch microbiota underlie the etiology of this idiopathic inflammatory condition. Here we present a detailed review of the data focusing on the pouch microbiota and the immune responses that support this hypothesis. We also discuss the contribution of luminal metabolic factors and the epithelial membrane in the etiology of this inflammatory process. The ileoanal pouch offers a unique opportunity to study the inter-relationships between the gut microbiota and host immune responses from before the onset of disease. For this reason the study of pouchitis could serve as a human model that significantly enhances our understanding of inflammatory bowel diseases in general.

The bacterial pathogenesis and treatment of pouchitis

Restorative proctocolectomy (RPC) with ileal pouch-anal anastomosis is the operation of choice for patients with ulcerative colitis. Pouchitis is the most common cause of pouch dysfunction. Although the pathogenesis of this disease is not well understood, bacteria have been implicated in the disease process. Numerous bacterial studies have been reported over the last 25 years with few unifying findings. In addition, many different treatments for pouchitis have been reported with varying results. Antibiotic treatment remains the most studied and is the mainstay of treatment. In this article we review the aetiology of pouchitis and the evidenced-based treatment options.

Treatment and prevention of pouchitis after ileal pouch-anal anastomosis for chronic ulcerative colitis

BACKGROUND

Pouchitis may occur following ileal pouch-anal anastomosis for chronic ulcerative colitis in approximately 30% of patients.

OBJECTIVES

The primary objective was to determine the efficacy of medical therapies for pouchitis (including antibiotic, probiotic, and other agents) as substantiated by data from randomized controlled trials (RCTs).

SEARCH STRATEGY

A search for RCTs from 1966 to October 2009 was performed using the MEDLINE, Cochrane Library, EMBASE, Web of Science, and Scopus databases.

SELECTION CRITERIA

Randomized controlled treatment or prevention trials of adult patients who underwent ileal pouch-anal anastomosis for ulcerative colitis who subsequently developed pouchitis or were at risk for pouchitis were considered for inclusion.

DATA COLLECTION AND ANALYSIS

Extracted data were converted to 2X2 tables and then synthesized in to a summary statistic using the Peto odds ratio (OR) and [95% confidence intervals], or weighted mean difference (WMD), using RevMan-5 for Mac OS 10.6.

MAIN RESULTS

Eleven RCTs fulfilled the inclusion criteria and were included in the review. The efficacy of 10 different pharmacologic agents was assessed. For the treatment of acute pouchitis (4 RCTS, 5 agents), ciprofloxacin was more effective at inducing remission than metronidazole. Neither rifaximin nor lactobacillus GG were more effective than placebo, while budesonide enemas and metronidazole were similarly effective, for inducing remission of acute pouchitis. For the treatment and maintenance of remission of chronic pouchitis (4 RCTs, 4 agents), glutamine suppositories were not more effective than butyrate suppositories, and bismuth carbomer foam enemas were not more effective than placebo, while VSL#3 was more effective than placebo in maintaining remission of chronic pouchitis in patients with chronic pouchitis who achieved remission with antibiotics. For the prevention of pouchitis (3 RCTs, 2 agents), in one study VSL#3 was more effective than placebo while in another study VSL#3 was not more effective than no treatment. Allopurinol was not more effective than placebo, while inulin was more effective than placebo but the results were not clinically significant.

AUTHORS' CONCLUSIONS

For acute pouchitis, ciprofloxacin was more effective than metronidazole, while budesonide enemas and metronidazole were similarly effective. For chronic pouchitis, VSL#3 was more effective than placebo. For the prevention of pouchitis, VSL#3 was more effective than placebo. Larger RCTs are needed to determine the optimal agent(s) for the treatment and prevention of pouchitis.

Laboratory tests for patients with ileal pouch-anal anastomosis: clinical utility in predicting, diagnosing, and monitoring pouch disorders

Restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA) is the surgical treatment of choice for patients with medically refractory ulcerative colitis (UC) or UC-associated dysplasia, and for the majority of patients with familial adenomatous polyposis. Pouchitis and other complications of IPAA are common. There are scant data on laboratory markers for the evaluation and diagnosis of pouch disorders. The presence of immunogenotypic markers such as genetic polymorphisms of interleukin-1 (IL-1) receptor antagonist, NOD2/CARD15, Toll-like receptor, and tumor necrosis factor-alpha has been reported to be associated with pouchitis. Immunophenotypic/serologic markers such as perinuclear antineutrophil cytoplasmic antibody and anti-CBir1 have been investigated as possible markers for predicting and diagnosing pouchitis. Fecal markers including lactoferrin and calprotectin seem to be useful in distinguishing inflammatory from noninflammatory pouch disorders. In our practice, we have encountered a large number of pouch patients with Clostridium difficile infection. Laboratory evaluation provides information on the etiology and pathogenesis of pouchitis, and it also helps practicing clinicians with accurate diagnosis, differential diagnosis, disease stratification, and management of ileal pouch disorders.

Pathogenesis of and unifying hypothesis for idiopathic pouchitis

Ileal pouch-anal anastomosis is the procedure of choice in the surgical management of refractory ulcerative colitis. Pouchitis affects up to 60% of patients following ileal pouch-anal anastomosis for ulcerative colitis. It overlaps significantly with ulcerative colitis such that improvements in our understanding of one will impact considerably on the other. The symptoms are distressing and impinge significantly on patients' quality of life. Despite 30 years of scientific and clinical investigation, the pathogenesis of pouchitis is unknown; however, recent advances in molecular and cell biology make a synergistic hypothesis possible. This hypothesis links interaction between epithelial metaplasia, changes in luminal bacteria (in particular sulfate-reducing bacteria), and altered mucosal immunity. Specifically, colonic metaplasia supports colonization by sulfate-reducing bacteria that produce hydrogen sulfide. This causes mucosal depletion and subsequent inflammation. Although in most cases antibiotics lead to bacterial clearance and symptom resolution, immunogenetic subpopulations can develop a chronic refractory variant of pouchitis. The aims of this paper are to discuss proposed pathogenic mechanisms and to describe a novel mechanism that combines many hypotheses and explains several aspects of pouchitis. The implications for the management of both pouchitis and ulcerative colitis are discussed.

Pouchitis: an evolving clinical enigma--a review

While the overall incidence of pouchitis is low, extensive research continues at clinical and experimental levels in attempts to unravel its etiology. The ileal pouch and pouchitis together represent a unique in vivo opportunity to study mucosal adaptation and inflammation in depth. In the recent past, molecular data relating to pouchitis has significantly expanded. These data provide invaluable insight into intracellular and extracellular events that underpin mucosal adaptation and inflammation. Advances in classification, risk factor evaluation, and prevention have meant that a review of this data, as well as its relationship to our current understanding of pouchitis, is both timely and warranted. Therefore, the aim of this review is to summarize recent data in the context of the established literature.

A prospective multivariate analysis of clinical factors associated with pouchitis after ileal pouch-anal anastomosis

BACKGROUND & AIMS

Although acute pouchitis (AP) after ileal pouch-anal anastomosis (IPAA) for UC is common and easily treated, chronic pouchitis (CP) remains a difficult management issue. The aim of this study was to identify important clinical risk factors associated with AP or CP.

METHODS

AP and CP were prospectively assessed, and demographic, disease, and treatment characteristics were tabulated. Univariate and multivariate analyses were performed to evaluate associations between AP or CP and potential risk factors.

RESULTS

Two hundred IPAA patients were followed for a median of 24 months (range, 3-117 months). Thirty-six patients (18%) developed AP, and 23 patients (12%) developed CP. On univariate analysis, the use of steroids before colectomy and smoking were associated with the development of AP. CP was associated with male gender, smoking, length of follow-up, extraintestinal manifestations, backwash ileitis, and elevated (450x10(9)/L) platelet count. On multivariate analysis, the following risk factors were found to be independently associated with AP: use of steroids before colectomy (odds ratio [OR], 3.7; 95% confidence interval [CI], 1.5-8.9; P = .004) and smoking (OR, 2.3; 95% CI, 1.1-5.3; P = .04). CP was directly associated with extraintestinal manifestations (OR, 3.5; 95% CI, 1.1-11.1; P = .03), elevated platelet count (OR, 3.1; 95% CI, 1.1-8.9; P = .03), and increased length of follow-up (OR, 1.3; 95% CI, 1.1-1.6; P = .002). Smoking reduced the incidence of CP (OR, 0.2; 95% CI, 0.05-0.74; P = .04).

CONCLUSIONS

Clinical factors associated with AP included use of steroids before colectomy and smoking. Factors directly related to CP were extraintestinal manifestations, elevated platelet count, and length of follow-up after IPAA. Smoking appears to protect against the development of CP.

Serologic responses in indeterminate colitis patients before ileal pouch-anal anastomosis may determine those at risk for continuous pouch inflammation

PURPOSE

Although acute pouchitis after ileal pouch-anal anastomosis is common and easily treated, continuous pouch inflammation seen clinically as chronic, antibiotic-dependent pouchitis, and/or Crohn's disease remains a difficult management problem. Compared with ulcerative colitis, indeterminate colitis patients undergoing ileal pouch-anal anastomosis have a higher incidence of continuous pouch inflammation, which may represent persistent immune reactivity to microbial antigens. Antibody responses to three microbial antigens (oligomannan anti-Saccharomyces cerevisiae, outer membrane porin C of Escherichia coli, and an antigen (I2) from Pseudomonas flourescens) are more commonly seen in Crohn's disease, whereas antibodies to a cross-reactive antigen (perinuclear antineutrophil cytoplasmic antibodies) is more suggestive of ulcerative colitis. We examined whether preoperative serologic responses to these antigens were associated with Crohn's disease in indeterminate colitis patients after ileal pouch-anal anastomosis.

METHODS

Twenty-eight indeterminate colitis patients undergoing ileal pouch-anal anastomosis were prospectively assessed for the development of pouchitis or Crohn's disease. Serologic responses were determined by enzyme-linked immunosorbent assay and immunofluorescence. Patients were classified based on four predominant profiles of antibody expression. Antibody profiles were determined before knowledge of clinical outcome.

RESULTS

Median follow-up was 38 (range, 3-75) months. Of 16 patients (61 percent) who developed pouch inflammation, 4 (25 percent) had acute pouchitis and 12 (75 percent) had continuous pouch inflammation (9 had chronic pouchitis, 3 had Crohn's disease). No preoperative clinical factor predicted the development of these pouch complications. Overall, 16 patients (57 percent) had a positive antibody reactivity profile. Serologic expression of any marker alone did not predict the development of continuous pouch inflammation. However, continuous pouch inflammation developed in 10 of 16 patients (63 percent) who had a positive antibody reactivity profile compared with only 2 of 12 patients (17 percent) who had a negative antibody reactivity profile (P = 0.015).

CONCLUSIONS

Indeterminate colitis patients who have a positive antibody reactivity profile before ileal pouch-anal anastomosis have a significantly higher incidence of continuous pouch inflammation after surgery than those with a negative profile.

Diagnosis and treatment of patients with pouchitis

Pouchitis is the most common long-term complication of ileal pouch-anal anastomosis in patients with underlying ulcerative colitis. Clinical symptoms of pouchitis are not specific, and they can be caused by other conditions such as rectal cuff inflammation and irritable pouch syndrome. Therefore, to make an accurate diagnosis, endoscopic evaluation together with symptom assessment is necessary. Among five available treat-first and test-first strategies, the initial approach with pouch endoscopy without histology was the most cost-effective strategy for the diagnosis of pouchitis. On the basis of clinical course, pouchitis can be classified into acute, relapsing and chronic forms. Pouchitis can also be classified into three categories based on the response to antibacterial therapy: antibacterial-responsive; antibacterial-dependent; and antibacterial-resistant. Metronidazole and ciprofloxacin are both effective in treating acute pouchitis. Although antibacterial therapy can induce and maintain remission, probiotics such as VSL#3 can also be used as to maintain clinical remission and prevent relapse in patients with relapsing or chronic pouchitis. For patients with chronic pouchitis that is resistant to antibacterials, therapy with anti-inflammatory agents and immunomodulators is often required.

Inflammatory bowel diseases: principles of nutritional therapy

Inflammatory Bowel Diseases - ulcerative colitis and Crohn's disease- are chronic gastrointestinal inflammatory diseases of unknown etiology. Decreased oral intake, malabsorption, accelerated nutrient losses, increased requirements, and drug-nutrient interactions cause nutritional and functional deficiencies that require proper correction by nutritional therapy. The goals of the different forms of nutritional therapy are to correct nutritional disturbances and to modulate inflammatory response, thus influencing disease activity. Total parenteral nutrition has been used to correct and to prevent nutritional disturbances and to promote bowel rest during active disease, mainly in cases of digestive fistulae with high output. Its use should be reserved for patients who cannot tolerate enteral nutrition. Enteral nutrition is effective in inducing clinical remission in adults and promoting growth in children. Due to its low complication rate and lower costs, enteral nutrition should be preferred over total parenteral nutrition whenever possible. Both present equal effectiveness in primary therapy for remission of active Crohn's disease. Nutritional intervention may improve outcome in certain individuals; however, because of the costs and complications of such therapy, careful selection is warranted, especially in patients presumed to need total parenteral nutrition. Recent research has focused on the use of nutrients as primary treatment agents. Immunonutrition is an important therapeutic alternative in the management of inflammatory bowel diseases, modulating the inflammation and changing the eicosanoid synthesis profile. However, beneficial reported effects have yet to be translated into the clinical practice. The real efficacy of these and other nutrients (glutamine, short-chain fatty acids, antioxidants) still need further evaluation through prospective and randomized trials.

Diagnosis and treatment of pouchitis

Total proctocolectomy with ileal pouch-anal anastomosis is the surgical procedure of choice for the management of ulcerative colitis. Pouchitis, a non-specific inflammation of the ileal reservoir, is the most frequent complication that patients experience in the long-term. Diagnosis should be made on the basis of clinical, endoscopic and histological aspects. The Pouchitis Disease Activity Index (PDAI) represents an objective and reproducible scoring system for pouchitis: active pouchitis is defined as a score > or = 7 and remission as a score < 7. About 15% of patients develop a chronic disease. Treatment of pouchitis is empirical, and very few controlled studies have been carried out. Antibiotics, particularly metronidazole and ciprofloxacin, are the treatment of choice. Chronic pouchitis may benefit from a prolonged course of a combination of antibiotics. Highly concentrated probiotics are effective for both prevention of relapses and prevention of pouchitis onset. There is no convincing evidence of the efficacy of other therapeutic agents.

Pouchitis in Children: Therapeutic Options

Pouchitis is an unfortunate common complication of the ileal pouch-anal anastomosis procedure, an otherwise very attractive surgical option in patients with ulcerative colitis (UC). The fact that the same pouch in familial polyposis is hardly complicated by pouchitis suggests that the basic inflammatory process in UC might participate in the pathophysiology. We review the clinical features of pouchitis, the diagnostic approach, and the many therapeutic considerations, including more recent data on prebiotics and probiotics.

Sulfate-reducing bacteria colonize pouches formed for ulcerative colitis but not for familial adenomatous polyposis

PURPOSE

Ileal pouch-anal anastomosis remains the "gold standard" in surgical treatment of ulcerative colitis and familial adenomatous polyposis. Pouchitis occurs mainly in patients with a background of ulcerative colitis, although the reasons for this are unknown. The aim of this study was to characterize differences in pouch bacterial populations between ulcerative colitis and familial adenomatous pouches.

METHODS

After ethical approval was obtained, fresh stool samples were collected from patients with ulcerative colitis pouches (n = 10), familial adenomatous polyposis (n = 7) pouches, and ulcerative colitis ileostomies (n = 8). Quantitative measurements of aerobic and anaerobic bacteria were performed.

RESULTS

Sulfate-reducing bacteria were isolated from 80 percent (n = 8) of ulcerative colitis pouches. Sulfate-reducing bacteria were absent from familial adenomatous polyposis pouches and also from ulcerative colitis ileostomy effluent. Pouch Lactobacilli, Bifidobacterium, Bacteroides sp, and Clostridium perfringens counts were increased relative to ileostomy counts in patients with ulcerative colitis. Total pouch enterococci and coliform counts were also increased relative to ileostomy levels. There were no significant quantitative or qualitative differences between pouch types when these bacteria were evaluated.

CONCLUSIONS

Sulfate-reducing bacteria are exclusive to patients with a background of ulcerative colitis. Not all ulcerative colitis pouches harbor sulfate-reducing bacteria because two ulcerative colitis pouches in this study were free of the latter. They are not present in familial adenomatous polyposis pouches or in ileostomy effluent collected from patients with ulcerative colitis. Total bacterial counts increase in ulcerative colitis pouches after stoma closure. Levels of Lactobacilli, Bifidobacterium, Bacteroides sp, Clostridium perfringens, enterococci, and coliforms were similar in both pouch groups. Because sulfate-reducing bacteria are specific to ulcerative colitis pouches, they may play a role in the pathogenesis of pouchitis.

Budesonide enema in pouchitis--a double-blind, double-dummy, controlled trial

BACKGROUND

Pouchitis has been suggested to be a recurrence of ulcerative colitis in a colon-like mucosa. Topical steroids are a valid therapeutic alternative for distal forms of ulcerative colitis.

AIM

To investigate the efficacy and tolerability of budesonide enema in the treatment of pouchitis compared with oral metronidazole.

MATERIALS AND METHODS

Twenty-six patients with an active episode of pouchitis (defined as a pouchitis disease activity index score >or= 7) and no treatment during the previous month were randomized to receive either budesonide enema (2 mg/100 mL at bedtime) plus placebo tablets or oral metronidazole (0.5 g b.d.) plus placebo enema in a prospective, double-blind, double-dummy, 6-week, controlled trial.

RESULTS

Based on the intention-to-treat principle, we detected a significant improvement in disease activity at the end of the first week with both drugs (P < 0.01). After that, improvement was moderated until stabilization at 4 weeks in both treatments. The per protocol analysis showed that both drugs had similar efficacy in terms of disease activity, clinical and endoscopic findings. Fifty-eight per cent and 50% of patients improved (decrease in pouchitis disease activity index >or= 3) with budesonide enema and metronidazole, respectively (odds ratio, 1.4; confidence interval, 0.2-8.9). Adverse effects were observed in 57% of patients given metronidazole and in 25% of patients given budesonide.

CONCLUSIONS

Budesonide enemas are an alternative treatment for active pouchitis, with similar efficacy but better tolerability than oral metronidazole.

Bile acid absorption after near-total proctocolectomy in dogs: ileal pouch vs. jejunal pouch-distal rectal anastomosis

Bile acid malabsorption is often present in patients after near-total proctocolectomy and ileal pouch-anal canal anastomosis, suggesting ileal dysfunction. Experiments were performed in dogs to compare bile acid absorption after a modified procedure, in which a jejunal pouch was interposed between the terminal ileum and the distal rectum, with that after a conventional ileal pouch operation. Fecal bile acid output (equivalent to hepatic bile acid biosynthesis) and composition were determined by gas chromatography/mass spectrometry in five jejunal pouch dogs and in five ileal pouch dogs more than 6 months after operation. Fecal bile acid output in the jejunal pouch dogs (mean +/- standard deviation) was 215 +/- 59 mg/day (10.1 +/- 2.7 mg/kg-day), a value similar to that obtained in the ileal pouch dogs (261 +/- 46 mg/day [12.8 +/- 3.1 mg/kg-day]; P >0.05). These values were also similar to those reported by others for healthy unoperated dogs, indicating that increased bile acid biosynthesis occurring in response to bile acid malabsorption was not present. Fecal bile acids in pouch dogs were completely deconjugated and extensively 7-dehydroxylated (jejunal pouch = 90.4% dehydroxylated; ileal pouch = 88.6% +/- 6.6% dehydroxylated) and consisted predominantly of deoxycholic acid derivatives. We conclude that when either a jejunal pouch or an ileal pouch is used as a rectal substitute in dogs, an anaerobic pouch flora develops that efficiently deconjugates and dehydroxylates bile acids, rendering them membrane permeable. The resultant passive absorption of unconjugated bile acids appears to compensate for any loss of active ileal absorption of conjugated bile acids, and bile acid malabsorption does not occur.

Endoscopic and histologic evaluation together with symptom assessment are required to diagnose pouchitis

BACKGROUND & AIMS

Pouchitis often is diagnosed based on symptoms alone. In this study, we evaluate whether symptoms correlate with endoscopic and histologic findings in patients with ulcerative colitis and an ileal pouch-anal anastomosis.

METHODS

Symptoms, endoscopy, and histology were assessed in 46 patients using Pouchitis Disease Activity Index (PDAI). Patients were classified as either having pouchitis (PDAI score > or =7; N = 22) or as not having pouchitis (PDAI score <7; N = 24).

RESULTS

Patients with pouchitis had significantly higher mean total PDAI scores, symptom scores, endoscopy scores, and histology scores. There was a similar magnitude of contribution of each component score to the total PDAI for the pouchitis group. Of note, 25% of patients with symptoms suggestive of pouchitis did not meet the PDAI diagnostic criteria for pouchitis. In both groups, the correlation coefficients between symptom, endoscopy, and histology scores were near zero (range, -0.26 to 0.20; P > 0.05).

CONCLUSIONS

The symptom, endoscopy, and histology scores each contribute to the PDAI and appear to be independent of each other. Symptoms alone do not reliably diagnose pouchitis.

Activation of signal-transducer and activator of transcription 1 (STAT1) in pouchitis

Activation of signal transducer and activator of transcription 1 (STAT1) is a hallmark of IFN-gamma receptor signal transduction but is also part of the signalling pathway of other cytokines/growth factor receptors. In ulcerative colitis, high levels of activation and expression of STAT1 have been observed in comparison with both Crohn's Disease and normal controls. Pouchitis develops in some patients after Ileal-Pouch-Anal-Anastomosis (IPAA). The pathophysiology and aetiology of pouchitis is still unclear. Recent studies have shown an increased production of proinflammatory cytokines including IFN-gamma. To investigate the expression and activation of STAT1 in pouchitis and the influence of treatment, patients were followed longitudinally from pouch operation. Diagnosis of pouchitis was made by clinical, endoscopic and histological criteria. Biopsies were obtained during routine endoscopy and snap frozen in liquid nitrogen. Nuclear and cytosolic extracts were prepared and the expression and activation of specific transcription factors were assessed by Western blot, electrophoretic mobility shift assay and immunofluorescence. Patients who develop pouchitis show highly increased levels of STAT1 alpha as well as STAT1 beta expression and activation in comparison with both normal pouch and normal ileal mucosa. Improvement of pouchitis during antibiotic therapy relates to a normalization of STAT1 expression and activation. We conclude that activation of STAT1 correlates to clinical disease activity and therefore STAT1 could play an important role in the pathophysiology of pouchitis. Similarities in the pattern of activation of STAT1 in pouchitis and ulcerative colitis may suggest a common pathway in the immunopathophysiology of both diseases.

Pharmacotherapy for inducing and maintaining remission in pouchitis

OBJECTIVES

To determine the effectiveness of medical therapy (including metronidazole, bismuth carbomer enemas, oral probiotic bacteria, butyrate suppositories, and glutamine suppositories) for inducing a response or maintaining remission in pouchitis.

SEARCH STRATEGY

Studies were selected using the MEDLINE data base (1966 - December 1997), abstracts from major gastrointestinal meetings and references from published articles and reviews. The Cochrane Controlled Trials Register and the Inflammatory Bowel Disease Review Group Trials Register were also searched.

SELECTION CRITERIA

Four randomized controlled trials of medical therapy in adult patients with pouchitis were identified: two placebo controlled trials in active chronic pouchitis; one maintenance of remission trial comparing two active agents in chronic pouchitis; and one placebo-controlled maintenance of remission trial for chronic pouchitis. A single patient "n-of-1" trial for active chronic pouchitis was excluded.

DATA COLLECTION AND ANALYSIS

Data were extracted by three independent observers based on the intention to treat principle. Each study was given a quality score based on predetermined criteria. Extracted data were converted to 2X2 tables (response versus no response and medical therapy versus placebo or medical therapy versus medical therapy) and then synthesized in to a summary statistic using the pooled odds ratio and 95% confidence intervals as described by Cochran and Mantel and Haenszel (the "odds ratio" in MetaView).

MAIN RESULTS

The odds ratios of inducing a response using oral metronidazole or bismuth carbomer foam enemas compared with placebo in active chronic pouchitis were 26.67 (95% CI 2.31-308.01) and 1.00 (95% CI 0.29-3.48), respectively. The numbers needed to treat with these therapies to prevent an additional relapse was 2 for oral metronidazole, and undefined for bismuth carbomer foam enemas (due to equal efficacy between the enema and placebo). The odds ratio of maintaining remission in chronic pouchitis for oral probiotic bacteria (VSL-3) compared with placebo was 205.00 (95% CI 9.89-4247.71), while the number needed to treat to prevent one additional relapse was 2. After discontinuation of suppressive medical therapy for chronic pouchitis, there was no difference in the odds ratio of maintaining symptomatic remission with glutamine suppositories compared to butyrate suppositories, 3. 00 (95% CI 0.46-19.59). The numbers needed to treat with glutamine suppositories to prevent an additional relapse was 4.

REVIEWER'S CONCLUSIONS

The results presented in this review must be interpreted with extreme caution given the small numbers of trials and patients evaluated for any one comparison. Metronidazole appears to be an effective therapy for active chronic pouchitis. Bismuth carbomer foam enemas may not be an effective therapy for chronic active pouchitis. Oral probiotic therapy with VSL-3 appears to be an effective therapy for maintaining remission in patients with chronic pouchitis in remission. There is no evidence of a difference in the maintenance of symptomatic remission in patients with chronic pouchitis treated with glutamine versus butyrate suppositories, and it is unknown whether glutamine and butyrate are equally effective or ineffective. Additional randomized, double-blind, placebo-controlled, dose-ranging clinical trials are needed to determine the efficacy of empiric medical therapies currently being used in patients with pouchitis.

Medical therapy for induction and maintenance of remission in pouchitis: a systematic review

OBJECTIVE

To determine the effectiveness of medical therapy (including metronidazole, bismuth carbomer enemas, oral probiotic bacteria, butyrate suppositories, and glutamine suppositories) for inducing a response or for maintaining remission in pouchitis.

SEARCH STRATEGY

Studies were selected using the MEDLINE data base (1966-December 1997), abstracts from major gastrointestinal meetings, and references from published articles and reviews.

SELECTION CRITERIA

Four randomized controlled trials of medical therapy in adult patients with pouchitis were identified: two placebo controlled trials in active chronic pouchitis; one maintenance of remission trial comparing two active agents in chronic pouchitis; and one placebo-controlled maintenance of remission trial for chronic pouchitis. A single patient "n-of-1" trial for active chronic pouchitis was excluded.

DATA COLLECTION AND ANALYSIS

Data were extracted by three independent observers based on the intention to treat principle. Extracted data were converted to 2 x 2 tables (response versus no response and medical therapy versus placebo or medical therapy versus medical therapy) and an odds ratio with 95% confidence intervals (CI) were determined as described by Cochrane and Mantel and Haenszel. In addition, the absolute risk reduction, relative risk reduction, and number needed to treat were determined.

MAIN RESULTS

The odds ratios of inducing a response using oral metronidazole or bismuth carbomer foam enemas compared with placebo in active chronic pouchitis were 12.34 (95% CI 2.34-64.95) and 1.00 (95% CI 0.29-3.42), respectively. The odds ratio of maintaining remission in chronic pouchitis for oral probiotic bacteria (VSL-3) compared with placebo was 15.33 (95% CI 4.51-52.14). There was no difference in the odds ratio of inducing symptomatic remission and then maintaining symptomatic remission after discontinuing suppressive medical therapy for chronic pouchitis with glutamine suppositories compared with butyrate suppositories, 2.75 (95% CI 0.48-15.94).

CONCLUSIONS

Metronidazole is an effective therapy for active chronic pouchitis. Bismuth carbomer foam enemas are not effective therapy for active chronic pouchitis. Oral probiotic therapy with VSL-3 is an effective therapy for maintaining remission in patients with chronic pouchitis in remission. There is no difference in maintenance of symptomatic remission in patients with chronic pouchitis treated with glutamine versus butyrate suppositories, and it is unknown whether glutamine and butyrate are equally effective or ineffective. Additional randomized, double-blind, placebo-controlled, dose-ranging clinical trials are needed to determine the efficacy of empiric medical therapies currently being used in patients with pouchitis.

The physiology of ileo-anal pouch function

Even excellent clinical function after ileo-anal pouch construction is associated with a variety of physiological abnormalities. Small bowel intestinal motility is essentially normal but the ileal reservoir serves to markedly suppress the ileal motor response both to progressive distension by intestinal contents and to transmitted myoelectrical complexes. As a result, the healthy pouch can accommodate a large volume of intestinal content before the rising baseline pressure and the appearance of large isolated contraction waves produce an urge to defecate. Evacuation in the normal pouch patient is rapid and highly efficient and is achieved by means of the Valsalva maneuver without any evidence of significant intestinal propulsion. External anal sphincter function is fully preserved but internal anal sphincter function is significantly impaired in the immediate postoperative period. Recovery occurs over the next 6 to 12 months but is often incomplete. Bacterial overgrowth in the pouch and prepouch ileum is almost universal and results in the premature deconjugation of primary bile salts and accumulation of secondary bile salts within the pouch. These produce morphologic changes in the ileal mucosa, and their excretion in pouch effluent gradually depletes the bile salt pool. Anerobic organisms also bind with vitamin B12 and the vitamin B12-intrinsic factor complex, resulting in subtle but measurable reductions in vitamin B12 levels in pouch patients. Finally, anerobic fermentation of mucus and undigested carbohydrate results in excessive quantities of short chain fatty acids within the pouch lumen. The clinical significance of these substances is unclear, but they may have an adverse action on both ileal mucosal and smooth muscle function. In essence, however, the pouch surgeon can maximize the likelihood of good clinical function by constructing a large capacity pouch, by avoiding surgery in patients with clearly deficient anal sphincter mechanisms, and by careful attention to pouch-anal anastomotic technique.

Crohn's-like complications in patients with ulcerative colitis after total proctocolectomy and ileal pouch-anal anastomosis

Total proctocolectomy with ileal pouch-anal anastomosis (IPAA) has become an established surgical procedure for ulcerative colitis. Occasional patients who have undergone IPAA develop persistent or recurrent episodes of pouchitis (chronic pouchitis), from which a subset also develop gastrointestinal and systemic complications that are identical to those seen in Crohn's disease. These complications include enteric stenoses or fistulas in the pouch or pouch inlet segment, perianal fistulas or abscesses, pouch fistulas, arthritis, iridocyclitis, and pyoderma gangrenosum. The development of Crohn's-like gastrointestinal complications in a patient with chronic pouchitis frequently engenders concern that the pathologist misinterpreted the proctocolectomy specimen as ulcerative colitis instead of Crohn's disease. We describe eight patients who developed chronic pouchitis and Crohn's-like complications after IPAA and total proctocolectomy. In each case, concern was voiced about misinterpretation of the proctocolectomy specimen as ulcerative colitis instead of Crohn's disease after the development of the Crohn's-like complications. Preoperatively, all eight patients had characteristic clinical, radiographic, and pathologic features of ulcerative colitis. Review of the pathology specimens indicated that all eight had ulcerative colitis. Crohn's-like complications are most likely related to chronic pouchitis, which probably is a form of recrudescent ulcerative colitis within the novel environment of the pouch. A diagnosis of Crohn's disease after IPAA surgery should only be made when reexamination of the original proctocolectomy specimen shows typical pathologic features of Crohn's disease, Crohn's disease arises in parts of the gastrointestinal tract distant from the pouch, pouch biopsies contain active enteritis with granulomas, or excised pouches show the characteristic features of Crohn's disease, including granulomas. There were no histologic differences in the total colectomy specimens between the eight ulcerative colitis study patients and 16 control ulcerative colitis patients who had a favorable clinical outcome after IPAA surgery groups. Crohn's-like complications and chronic pouchitis does not necessarily imply an incorrect original interpretation of ulcerative colitis by the pathologist.

Ileal pouches: adaptation and inflammation

Ileal pouch-anal anastomosis (IPAA) has become the operation of choice following proctocolectomy for ulcerative colitis (UC) and familial adenomatous polyposis. Functioning ileal pouch mucosa undergoes histological changes resembling the colon (colonic metaplasia). The possible role of stasis and luminal factors--bile acids, short-chain fatty acids and bacteria--are discussed. It seems likely that colonic metaplasia is an adaptive response to the new luminal environment in IPAA. Inflammation in the ileal reservoir ('pouchitis') is the most significant late complication in IPAA. It occurs in 20-30% of patients and is virtually confined to those with prior UC. The clinical picture in pouchitis is highly variable; however, it can be easily categorized into three groups. Nevertheless, in most cases it is likely to represent recurrent UC in the ileal pouch. Current treatments and possible preventative strategies for pouchitis have been outlined.

Pouchitis after ileal pouch-anal anastomosis for ulcerative colitis occurs with increased frequency in patients with associated primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC), present in 5% of patients with ulcerative colitis, may be associated with pouchitis after ileal pouch-anal anastomosis. The cumulative frequency of pouchitis in patients with and without PSC who underwent ileal pouch-anal anastomosis for ulcerative colitis was determined. A total of 1097 patients who had an ileal pouch-anal anastomosis for ulcerative colitis, 54 with associated PSC, were studied. Pouchitis was defined by clinical criteria in all patients and by clinical, endoscopic, and histological criteria in 83% of PSC patients and 85% of their matched controls. PSC was defined by clinical, radiological, and pathological findings. One or more episodes of pouchitis occurred in 32% of patients without PSC and 63% of patients with PSC. The cumulative risk of pouchitis at one, two, five, and 10 years after ileal pouch-anal anastomosis was 15.5%, 22.5%, 36%, and 45.5% for the patients without PSC and 22%, 43%, 61%, and 79% for the patients with PSC. In the PSC group, the risk of pouchitis was not related to the severity of liver disease. In conclusion, the strong correlation between PSC and pouchitis suggest a common link in their pathogenesis.